New bill comes as state struggles to acquire chemicals to carry out lethal injection executions.

The new bill could see firing squads and gas chambers added to Mississippi's execution methodsReuters

Legislators in Mississippi are bringing forward proposals to allow firing squads as a possible execution method as it struggles to acquire the drugs used for lethal injections. House Bill 638 lays out a sequence of methods that could be used if others are ruled unconstitutional or are simply unavailable.

If lethal injections are not possible, the bill states, then a gas chamber will be used. If that is unavailable, "then the sentence of death shall be carried out by firing squad". If that is also unavailable, then electrocution is the next method.

The Associated Press (AP) reported that the state of Mississippi has not been able to acquire the drugs it previously used for lethal injections for some time, having last carried out an lethal injection execution in 2012.

Three states still authorise hanging – Delaware, New Hampshire and Washington, while five allow gas chambers – Arizona, California, Missouri, Wyoming and Oklahoma.

DPIC says only three executions by firing squad have taken place in the US since 1976 and the same number of hangings. Only 11 gas chamber executions have taken place in that time. Republican Mississippi state representative, Andy Gipson, told the news agency that the bill was a response to legal action by "liberal, left-wing radicals".

In 2015, Utah brought back firing squads when the state too found itself having trouble acquiring the usual chemicals. At the time, Utah Governor Gary Herbert even admitted that firing squad executions were "a little bit gruesome".